This invention relates to certain Group 3,4 and Lanthanide metal complexes comprising a cyclic, or noncyclic, non-aromatic, anionic, dienyl group wherein the metal of said complexes is in the +3 formal oxidation state and further wherein the metal is also covalently bonded via a second ligand group to the cyclic or noncyclic, non-aromatic, anionic, dienyl ligand group. The invention also relates to techniques for preparing such complexes, catalyst systems comprising such complexes that are useful for polymerizing addition polymerizable monomers, and to such polymerization processes themselves.
Metal complexes containing delocatized, .PI.-bonded ligand groups and methods for their preparation are disclosed in U.S. application Ser. No. 545,403, filed Jul. 3, 1990, pending (EP-A-416,815); U.S. application Ser. No. 547,718, filed Jul. 3, 1990, abandoned (EP-A-468,651); U.S. application Ser. No. 702,475, filed May 20, 1991, abandoned (EP-A-514,828); U.S. application Ser. No. 876,268, filed May 1, 1992, pending (EP-A-520,732) and U.S. application Ser. No. 8,003, filed Jan. 21, 1993, now U.S. Pat. No. 5,374,696 (WO93/19104), as well as U.S. Pat. No. 5,055,438, U.S. Pat. No. 5,057,475, U.S. Pat. No. 5,096,867, U.S. Pat. No. 5,064,802 and U.S. Pat. No. 5,132,380. The teachings of all the foregoing patents, publications and patent applications are hereby incorporated by reference
Despite the advance in the art brought about by the foregoing metal complexes, new and improved catalytic compounds are still desired.